Domnica ( 378) was the wife of Roman emperor Valens. Valens, who ruled from 364 to 378, was emperor of the East and co-emperor with his brother Valentinian I. After the death of her husband in 378 she ruled as de facto regent and defended Constantinople against the attacking Goths until his successor, Theodosius I arrived. Family Dominica was the daughter of the powerful and unpopular praetorian prefect Petronius, who was hated for his greed and cruelty. Her father's unpopularity was so great that it led to the rebellion of Procopius, a rival of Valens, in 365. According to the account of Ammianus Marcellinus: "To the emperor's cruelty deadly incentive was given by his father-in‑law Petronius, who from the command of the Martensian legion had by a sudden jump been promoted to the rank of patrician. He was a man ugly in spirit and in appearance, who, burning with an immoderate longing to strip everyone without distinction, condemned guilty and innocent alike, after exquisite tortures, to fourfold indemnities, looking up debts going back to the time of the emperor Aurelian, grieving excessively if he was obliged to let any one escape unscathed." Petronius was probably a Pannonian. Her further ancestry is unknown. Various of her relatives held influentials positions. A possible relative is Domnicus, an officer of Valens mentioned in Oration II by Libanius. Procopius, prefect of Constantinople in 377, is mentioned by Zosimus as a relative of Valens by marriage. Suggesting he was also related to Dominica. According to Nicetas of Serra, Eusebius was her uncle and a praefectus urbi in the Diocese of Pontus. Nicetas was a commentator to the works of Gregory of Nazianzus and identified Eusebius with an otherwise unnamed figure mentioned in the works of Gregory. Eusebius is thus supposedly recorded in the funeral oration in honor of Basil of Caesarea. The names Anastasia, Domnicus, Eusebius, Petronius and Procopius used by various family members are thought to be Greek in origin. Various scholars have suggested this could indicate the descent of Dominica and her relatives from Greek-speaking families of Sirmium, the initial capital of the Praetorian prefecture of Illyricum. Marriage into a Greek family could have helped solidify Valens' rule over the Hellenized Eastern Roman Empire. Marriage She married Valens (c. 354) and bore two daughters, Anastasia and Carosa, before she bore a son and heir, Valentinianus Galates (366–370). According to Socrates of Constantinople and